
import sys
input = sys.stdin.readline
def inp():
    return(int(input()))
T = inp()
print("No") if T<30 else print("Yes") import sys sys input = sys.stdin.readline input sys.stdin.readline sys.stdin sys stdin readline def inp():
    return(int(input())) inp return(int(input())) int(input()) int input() input T = inp() T inp() inp print("No") if T<30 else print("Yes") T<30 T 30 print("No") print "No" print("Yes") print "Yes" input = sys.stdin.readline sys.stdin.readline input def inp():
    return(int(input())) def inp():
    return(int(input())) inp T = inp() inp() T

import sys
input = sys.stdin.readline
def inp():
    return(int(input()))
T = inp()
print("No") if T<30 else print("Yes")
